1. Technical Field
The present invention relates generally to aquarium filtration devices. More particularly, the present invention relates to combination biological, mechanical and chemical filtration systems that simulate natural tidal conditions.
2. Related Art
Keeping fish and other marine life in a home aquarium is a popular hobby with varying levels of complexity and sophistication. At the simplest level, there are freshwater aquaria with fish such as guppies, goldfish, and the like, though other less common species such as angelfish and rainbowfish may also be kept. In addition to fish, such freshwater aquaria may also include aquatic plants for environmental balance and aesthetic purposes. The aquatic plants typically foster growth of beneficial bacteria and other microorganisms that facilitate aquarium health. At the more complex levels, exotic and colorful saltwater fish may be kept, along with appropriate aquatic plants. The appearance and longevity of such a saltwater aquarium may be enhanced by the addition of living rock, that is, structures composed of calcium limestone and decomposing coral skeleton that foster the growth of algae, worms, and other small marine organisms. Furthermore, a reef ecosystem may be implemented by the addition of living coral.
The environment within the aquarium would ideally have an ecological balance identical to that of the natural habitat of the life forms therein, but sustained and consistent balance is practically impossible due to the limited size thereof. The limited volume of water in typical hobbyist aquaria results in a reduction of its capacity to absorb systemic shocks such as death or the addition of a fish or plant, and further leads to a deterioration of long-term ecological stability. Accordingly, maintenance of a proper chemical and biological balance represents a significant challenge in keeping an aquarium. More particularly, proper nutrient cycles must be maintained, including the oxygen cycle, the nitrogen cycle, the sulfur cycle, and so forth. Sufficient levels of oxygen must be present in the aquarium water for respiration, and the resultant carbon dioxide must be expelled. Further, waste products expelled by fish and aquatic plants resulting from consumed food and other nutrients must be removed. Unconsumed nutrients and food particles may also remain in the water that may have an adverse affect on the ecology of the aquarium, and so such compounds likewise must be removed. Secondary waste products may also be generated by bacteria that ingest the primary waste from the fish. The aforementioned impurities may be harmful, and even lethal to the fish and other organisms in the aquarium at high concentrations.
Of particular concern with respect to aquarium maintenance is the nitrogen cycle, which relates to the breakdown process of nitrogen waste. In conjunction with proper feeding, appropriate maintenance of the nitrogen cycle is deemed sufficient for most aquaria because the other nutrient cycles are essentially maintained in equilibrium so long as the nitrogen cycle is at equilibrium. As understood, ammonia or nitrogenous waste is produced by fish directly or via feces, as well as by plants, animal matter, and uneaten food that is decomposing. In a natural environment, ammonia is neutralized by a two-step process known as nitrification. A first type of beneficial bacteria known as nitrifiers, or Nitrosomonas, metabolizes the ammonia from the water and produces nitrite. Nitrite is also understood to be toxic to fish in high concentrations, though not as toxic as ammonia. A second type of beneficial bacteria, the Nitrospira, converts the nitrite to nitrate, which is harmless to the fish. In addition to the bacteria, aquatic plants may also convert ammonia to nitrate. Both of these types of bacteria are aerobic, and thus depend upon a supply of oxygen.
Considering the limited ecology of a typical home aquarium, relying upon the above-described biological processes to occur naturally without human intervention is largely inadequate. In this regard, wide varieties of biological filtration systems have been conceived and are known in the art. Generally, such filtration systems foster the growth of the aforementioned bacteria by providing biomedia with a large surface area upon which the bacteria may grow. Typical biological filters are of the wet/dry type, where water from the aquarium is pumped and trickled over the biomedia. This oxygenates the water, thereby providing sufficient oxygen for the aerobic bacteria to nitrify the ammonia present in the water.
Before the water from the aquarium contacts the biomedia, it may undergo mechanical filtration to remove large debris and contaminants. This is done because the biological filter must be clear of large debris that would impede the flow of water and reduce oxygenation efficiency. The most common type of mechanical filter utilizes gravel and/or synthetic fibers that trap solid waste products.
In addition to the foregoing mechanical filtering for debris, the water from the aquarium may undergo a chemical filtration process. Such chemical filters remove or deactivate organic substances before breaking down into nitrogen waste, thus decreasing the filtration load upon the biological filter. Activated carbon and ion-exchange resin filters may be utilized to this end. Alternatively, yet increasingly, devices known as protein skimmers, or foam fractionators are used. A conventional protein skimmer includes a column of water with fine bubbles passed therethrough. Protein and other compounds bind to the air in the bubbles, and are carried to the top of the column. The resulting foam is collected, allowed to condense, and subsequently removed.
Conventional aquaria utilize one or more of the above-described mechanical, chemical, and biological filtration systems, either alone or in combination, depending on the sensitivity of the fish and marine life being kept. Existing systems, however, are configured to filter water at a consistent rate, and cannot accurately simulate ecological conditions in tidal pools. In addition to the Nitrosomonas and Nitrospira bacteria, there are other types of bacteria that facilitate aquarium health. Some types have higher effectiveness when mostly submerged, while others have higher effectiveness when in contact with the air. A natural tidal pool environment is capable of accommodating all such bacteria, yet conventional filtration systems are unable to do so, leading to inefficient or unsatisfactory bacteria cultivation.
Accordingly, there is a need in the art for an aquarium filtration system including biological and chemical filtration components that simulate natural tidal conditions to accommodate a wide range of marine life. There is also a need in the art for a cyclical aquarium filtration system with a minimal number of moving parts for maintenance and cleaning ease.